Liquid-level gauge



H. D. PowNALL Er Al.

April 23, '1929.

" LIQUID LEVEL GAUGE Filed July 9, 1924 2 Sheets-Sheet April 23, 1929.

H( D. PowNALL Er AL. 1,709,875

LIQUID LEVEL GAUGE Filed July 9, 1924 2 Sheets-Sheet 2 I N VENTOR.

By 7M. @mwa/77C A TTORNEY.

Patented Apr. 23, 1929-.

UNITED s'lzarlasv PATENTl OFFICE.

HENRY D. POWNALL AND FRANK IVI.v BENNETT, OF CANTON, OHIO; SAID POWNALL AS- SIGNOR, BY MESNE ASSIGNMENTS, TO

YORK ICE MACHINERY CORPORATION, F

YORK, PENNSYLVANIA, A CORPORATION 0F DELAWARE.

LIQUID-LEVEL GAUGE.

\ Application filed July 9,

Our invention relates to improvements in iquid level gauges. One of its objects is zo provide an improved liquid level gauge for use with steam and liquefied gases, and for other similar purposes. Another object s to provide an improved liquid level gauge Ldapted to register on a floor or other loca- ;ion above the location of the liquid con- ;ainer. Another object is to provide a iquid level gauge which may be used with ;afety in connection with liquefied gases or )ther liquids which give off poisonous or langerous fumes or vapors. Another object s to provide a gauge the readings of which tre not liable to be obscured by the forma- ;ion of frost'or ice thereon. Another obect is to provide an improved liquid level gauge in which a broken gauge glass tube nay be safely replaced even where the gauge s employed to indicate the liquid level of iquefed ammonia gas, liquefied chlorine gas, water in a boiler under high pressure, or inder like circumstances where to replace i gauge tube would ordinarily be dangerous. Dur invention also comprises certain details )f form and combination of components, ill of which will be fully set forth in the lescription-of the accompanying drawings n which:

Fig.l 1 is a central vertical section through )ur improved liquid gauge and a liquid storage reservoir the liquid levelin which it is desired to indicate.

Fig. 2, is an enlarged sectional detail view taken on line 2-2 of Fig. 1.

Fig. 3, is a. central'sectional View of a perforated bushing detached.

Fig. 4, is a perspective View of the liquid level indicator.

' Fig. 5, is an enlarged sectional detail view 3f a portion of Fig. 1.

Fig. 6, is a View similar to Fig. 5 illustrating a modification thereof.

The accompanying drawings illustrate the preferred embodiments of our invention in which represents a liquid storage reservoir, as for instance the brine cooler of an artificial ice machine in which tank is stored a body of liquefied anhydrous ammonia or other liquefied gas used as a refrigerant, and having a liquid level line 16 usually maintained in the upper portion of said tank so as to submerge the flue tubes 17 in such liquid. A liquid level indicator tank 18, prefer- 1924. serial N9. 725,074.

ably a vertical cylindrical container is located adjacent to the main reservoir 15 at one side thereof. A connecting conduit 19 'having a controlling valve 20,l and preferably a flange union 21 serves to connect the upper portion of the reservoir 15 with the upper portion of the indicator tank 18. r1`he conduits 19 and 22 at the top and bottom of the tank 18 enable the gas and liquid in the tank 18 to flow to or from the tank 18 to automatically find and keep a true and reliable liquid level within the tank 18. A connecting` conduit 22 having a controlling valve 23 and preferably a flange union 24 serves to connect the lower portion of reservoir 15 with the low-er portion of the indicator tank 18.

A branch conduit 25 provided with a controlling valve 26 serves convenient to take the liquid level readings at a distance from the reservoir 15. As illustrated and as applied to an artificial ice machine, it is 'designed that both the reservoir 15 and the tank 18 be submerged in brine in a brine cooler tank, not shown, of which brine cooler tank the floor 28 represents the cover, arrangements being made to gmaintain a ra )id circulation of brine both through the ues 17, and also in contact with the exterior face of the reservoir 15 ,in order to efliciently exchange heat from the brine into the liquefied gas within the reservoir 15 thereby causing ebullition of the liquid within the reservoir 15 to use up the heat so absorbed. Liquefied gas isregularly supplied through a valve controlled conduit, not shown, to the reservoir 15 to take the place of that evaporated, and the vapor or gas developed in the reservoir'15 is conducted away to a gas compressor thrqugh a valve controlled conduit, not shown, leading from the upper portion of the reservoir 15.

Due to the conduits 19 and 22 .the liquid level is maintained at an equal height in both the reservoir 15 and the tank 18, and any iuctuation of the liquid level in the reservoir is correspondingly indicated in the tank 18. A sheet metal float 30 Heats or rides on the surface of the liquid in the tank 18 and rises and falls to correspond to fluctuations in the liquid level from time to time in the reservoir 15 and tank 18. Rigidly attached to the upper face of thc float 30 is a vertical tempered steel rod or' wire 31 which also rises and fallsv with the float 30.

The upper head 32 of the tank 18 is provided with a threaded perforation 33 through which the rod 31 projects upwardly and with' a stuiing or packing box 34 and packing gland A metallic sleeve or bushing 36 is threaded into the perforation and has a central bore 37 of only slightly greater diameter than the diameter of the rod 31, as for instance a difference .in diameter of onevto two thousandths of an inch. The bushing 36 is preferably of tempered steel and accurately and smoothly drilled and finished and is seated in the upper head 32 below the stuffing box 34 with the rod 31 projecting upwardly through its bore with only sutlicient clearance for the rod 31 to move freely upwardly and downwardly through the bore of the bushing 36 and with very little space between the rod 31 andthe walls of the bore 37 through which gas or liquid might escape upwardly from the tank 18.

The gauge tube 38 of transparent material is supported and centered at its lower end upon the bushing 36 and is surrounded with the packing in the stuffing box 34 to provide a gas tight'joint between the lower end of the gauge tube 38 and the head 32. A nut 39 is threaded to a flange 40 on the head 32 to force the packing and the gland 35 into the stuiiing box. A metal tube 42 substantially concentric with the tube 38 is threaded to a flange 43 on the head 32 to serve as a guard and protecting housing for the tube 38. The tubel 42 is slotted longitudinally at 50 to enable the gauge tube 38, a liquid level scale 420 attached to said tube 42 and a liquid level pointer or indicator 44 to be observed through the slots in the tube 42.

As illustrated in Figs. 1 and 5 the sleeve or bushing 36 is threaded into the perforation 33 from below preferably by means of a spanner wrench engaging recesses 362 in the head of bushing 36. A reduced tubular section 361 of the bushing serves to center or vguide the lower end of the gauge tube into position.

In the modification Fig. 6, the bushing 360 corresponding to the bushing 3 6 of Figs. 1, and 5 is introduced from above, and is preferably threaded into the lower end of the stufing box 340 preferably by means Aof a Spanner wrench engaging recesses 364 at th top of the bushing 360. The bushing 360 i counter-bored at 365 toreceive and guid the lower end of the gauge tube into posi tion with reference to the bushing 36() aml the stuffing box. The bushing 36() is pro vided with a restricted orifice 370 corre sponding to the orifice 3T of Fig. 5.

At the upper end of the tube 42 is a meta cap 45 threaded to the tube 42. The e211 45 is preferably perforated to receive i gland 46 which is threaded to the cap 4 and serves to apply tension to an annulai 'packing located in the stuiiing box 47 to pro vide a gas tight joint between the cap 4." and the upper end of the gauge tube 38 Other means than that shown may be em ployed to secure a gas tight joint at th( upper end of the tube 38.

Mounted upon the upper end of the rot 31 is an indicator or pointer 44 preferir-bij a colored cylinder of cork or other relatively light weight material held in plac( relative to the rod 31 for instance by mean.` of nuts 48 and 49 threaded to the rod 3] above and below the pointer 44. The point- Aer 44 moves vertically within the tube 3t with the rod 31 andthe fioat 3() to indicate upon a scale such `as shown at 420 iii Fig. 1 for instance, or which ma)v be attached to or' cut upon the gauge tube 38 oi inclosed with the tube 38 within the tub( 42. The rod 31 and pointer 44 being of relatively light weight compared with the displacement capacity of the float 30, enable the readings to be taken with accuracy on the next floor above the tank 18 and reservoirv15, which is an important advantage. Also due to the small space available for the escape of ammonia vapor, live steam or other gas or vapor liable to be contained in the tank 18 with the liquid to be gauged. there is practically no danger in the event of the gauge tube 38 being accidentally fractured of any considerable escape of gas or. an injury to any one in the vicinity thereof or any necessity to close down the operation of the apparatus in order to replace a gauge tube since the amount of gas or vapor leakage possible is so small as not to lie objectionable or dangerous to an operator' engaged in replacing the gauge tube.

The apparatus .herein shown and dcscribed is capable of considerable modificationA within the scope of the claims without departing from the spirit of lour invention.

What we claim is:

1. A liquid level gauge comprising afloat chamber, a float supported uponand movable vertically with a column of liquidwithin said float chamber, a rod carried by and projecting upwardly from said float and movable vertically with said float, there being a restricted orifice in the upper end of member is movable to indicate variations in 'the liquid level within said fioat chamber, and a gas tight housing normally enclosing the upper end of said rod and said indicator member and provided with a transparent `section through which the movements of said indicator member may be observed.

2. A liquid level gauge comprising a float chamber, a float supported upon and movable vertically with a column of liquid within said fioat chamber, there being a restricted orifice in the upper end of said float chamber, a rod carried by and projecting upwardly from said float through said restricted orifice and having unhampered movement vertically through said restricted orifice and at the same time through a close approximation to the bore of said orifice adapted to4 prevent the escape of any appreciable volume of gas through said orifice past said rod, an index scale, an indicator member mounted upon said rod above said restricted orifice and movable o ver said index scale to indicate variations in the liquid level within said\ fioat chamber, a gauge tube of transparent material detachably mounted above said restricted orifice and within which said rod and indicator member are free to move vertically, a perforated tubular housing for said gauge tube mountedrigidly relative to said float chamber, a cap mounted upon the upper end of said gauge tube housing and serving as a support for the upper end of said gauge tube and to take the end thrust of said gauge tube, and means to form gas tight oints at opposite ends of said gauge tube.

3. A liquid level gauge comprising a fioat chamber, a float supported upon and movable vertically with a column of liquid within said float chamber, there being a restricted orifice in the upper end of said fioat chamber, a rod carried by and projecting upwardly from said float through said restricted orifice and having unhampered movement vertically with said float, said restricted orifice serving to prevent, the escape of any appreciable volume o f 'gas through said orifice and past said rod due to the small amount of clearance` space intervening between the wall of said orifice and the face of said rod, an indicator member i mounted upon said rod above said restricted orifice and movable with said rod, a stationarily mounted index scale over which said indicator moves to indicate variations in the liquid level within said float chamber, a

gauge tube of transparent material closed at its upper end with a gas tight joint and detachably mounted with a substantially gas tight joint to the exterior of said fioat chamber above said restricted orifice and Within which gauge tube said rod and indicator member are free to move vertically, a tubular housing vmember for said gauge tube mountedrigidly relative to said fioat chamber and having a perforation through which the movements of said indicator member may be observed.

4. A liquid level gauge comprising a iioat chamber having independent conduits near the upper and lower ends thereof respectively for the flow of liquid and gaseous portions of the medium to be gauged to and from said float chamber, a float supported upon and movable vertically with a column of liquid within said fioat chamber, said fioat chamber having a restricted orifice at its upper end, a rod carried bysaid float and projecting upwardly therefrom and projecting with a close fit through said restricted orifice, said rod having unhampered movement through said orifice and at the same time adapted to prevent the escape of any appreciable volume of gas through said orifice past said rod, a gauge tube housing carried rigidly relativeto said float chamber, a cap at the outer end of said housing, a gauge tube of transparent material supported at one end by said float chamber concentrically with said orifice and at the opposite end by the cap of saidvhousing, means to form gas tight joints at opposite ends of said gauge tube, an indicator scale, and an indicator. carried by said rod Within said gauge tube adapted to indicate upon said scale changes in the liquid level within said fioat chamber.

5. A liquid level gauge comprising a float chamber, a fioat supported upon and movable vertically with a column of liquid within said fioat chamber, said fioat chamber being provided with a perforation through its upper end, a bushing rigidly mounted in said perforation and provided with a restricted orifice, a rod carried by said fioat and projecting upwardly through the restricted orifice in said bushing and having unhampered movement vertically with said float and at the same time adapted to prevent the escape of any appreciable volume of gas through said orifice past said rod, a gauge tube fitted to the upper end of said bushing, a stuffing boxabove said bushing to provide a tight jointfbetween the lower end of said gauge chamber, a fioat supported upon and movable vertically with a column of liquid With- .in said float chamber, said float chamber having a perforation through its top wall, a bushing threaded into said perforation and provided with a restricted orifice, a rod carried by and projecting upwardly from said iioat through said restricted orifice and having unhampered movement vertically with said oat and atthe same time adapted to prevent the escape of any appreciable volume of gas through said orifice past saidy rod,l a gauge tube fitted to the upper end of said bushing, a stuiiing box above said bushing to provide a tight joint between the lower end of said gauge tube and the top wall of'said float chamber, means to sup-port the free end of said gauge tube, a stuiing box at the free end of said gauge tube, an index scale, and an indicator mounted upon said rod within said gauge tube and movable with said rod and float to indicate upon said scale variations in the liquid level within said float chamber.

In testimony whereof we have hereunto aiiixed vour signatures.

H. D. POVNALL. FRANK M. BENNETT. 

